Regular virologic surveillance showed very frequent cytomegalovirus reactivation in patients treated with alemtuzumab.

Ten patients with refractory lymphomas or autoimmune cytopenias were treated with alemtuzumab, and monitored prospectively for cytomegalovirus (CMV) reactivation by antigenemia and polymerase chain reaction. All patients showed virologic CMV reactivation. Two patients developed pneumonitis and hepatitis respectively, necessitating alemtuzumab withdrawal. Eight patients were asymptomatic, and with pre-emptive anti-CMV treatment, alemtuzumab therapy was uninterrupted. All patients ultimately achieved virologic remission. The frequent CMV reactivation was due to a high background seropositivity rate for CMV, severely immunocompromized patients, a sensitive detection method, and the diligence of surveillance. Frequent monitoring for and early treatment of CMV reactivation is necessary during alemtuzumab therapy. (c) 2006 Wiley-Liss, Inc.